What's this noise? (Squeal while recording.)

[billybobjo]

While recording anything through my mic on my PC I get this weird squeaking/squealing noise (see link below for sound clip). It's not the mic and not a driver related issue (tested with multiple drivers in windows and linux).

Anybody got any ideas? Is it interference, should I try a PSU change or is it more likely a soundcard fault?

http://www.emberspawn.com/sound.wma

Thanks for any help!

[kozikowski]

That's impressive on so many levels. FireFox tried to load and play the file and hung. I had to sudo kill -9 to get control of the machine back.

What's the possibility of getting something other than a proprietary Windows Media sound file posted (said the Mac user)?

Koz

[kozikowski]

Never mind. I forced it to work.

Something is oscillating. Pull out any sound plugs and connectors and scrub them with simple glass cleaner or vodka (I'm not kidding) and a paper towel. If you can't get to them easily. just pull and push back in several times.

Wiggle any sound connections while you make another recording. If nothing you do outside makes any difference, the sound card may be --not necessarily damaged, but badly connected to the computer. Bad grounds, shields, and earth connections do this all the time.

Try to change the gain sliders very slightly and listen for a change. Something in the computer is "singing" or generating its own sound signals in addition to your show. It could be two somethings, a process that's supposed to be there and a rogue signal. The combination has given you that heterodyne beat sound.

Koz

[steve]

or it could be RF interference,or heterodyne modulation from an unstable clock signal, or from a power supply...
Interesting that its in one channel only. That could be due to a bad connection on one audio lead as Koz suggested, or it could be due to a badly designed circuit board that send one audio signal across a board too close to a noisy component.

[kozikowski]

You might try plugging something into the audio connections of the computer several times just to make sure corrosion or bad connections aren't the problem.

I'm putting money on an analog problem. This is so like bad connection problems I've had to service for years. The microphone connection in your computer is the most likely to do something like that. If you have a "+20dB Boost" setting in your Control Panels, try turning that off.

Even if you can't actually get rid of it, if you manage to change it at all, that's insanely good to know.

Does it change when you plug in the wall power?

Koz

[billybobjo]

I've tried wiggling connectors, moving the pc to a different room and changing every component I could feasibly try (microphone, graphics card, psu). Nothing removed or even changed the sound. The only thing left to blame is a bad soundchip on the motherboard, I think it's RMA time.

[kozikowski]

<<<It's not the mic >>>

And you know that because you tried a different microphone? What is the microphone?

Koz